Re: Big mallocs, mmap sorrows and double buffering.

John Wyszynski (wyszynsk@clark.net)
Mon, 17 Feb 1997 20:26:35 -0500


> Matti Aarnio <matti.aarnio@tele.fi> writes:
> | > Since PROT_WRITE is not set this is in effect a shared mapping (and Linux
> | > internally handles it like a shared mapping).
> |
> | Hmm.. Ok, perhaps it is so. It just isn't obvious.
>
> The down side is that where write() returns status, mmap() gives you a
> segmentation fault or bus error if the write failed for any reason
> (like, the disk got full). Also, there's no analog to fsync() to make
> sure that the data has actually hit stable storage.
>
Yes there is, it's called "msync". It's more flexible in that the range to
be sync'd is specified.

John